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Wang Y, Lu J, Ruth M, MacNaughton K, Kelly S, Shi D, Goruk S, Glimm D, Reaney M, Vine D, Field C, Proctor S. Novel hypolipidemic properties of trans-11 vaccenic acid is partially due to reduced chylomicron production and improved postprandial lipaemia in the JCR:LA-cp rat. ATHEROSCLEROSIS SUPP 2008. [DOI: 10.1016/j.atherosclerosissup.2008.09.430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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102
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Dieguez-Gonzalez R, Calaza M, Shi D, Meulenbelt I, Loughlin J, Tsezou A, Dai J, Malizos KN, Slagboom EP, Kloppenburg M, Chapman K, Jiang Q, Kremer D, Gomez-Reino JJ, Nakajima N, Ikegawa S, Gonzalez A. Testing the druggable endothelial differentiation gene 2 knee osteoarthritis genetic factor for replication in a wide range of sample collections. Ann Rheum Dis 2008; 68:1017-21. [PMID: 18625619 DOI: 10.1136/ard.2008.093641] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To replicate a previously reported association with osteoarthritis (OA) of the promoter single nucleotide polymorphism (SNP) rs10980705 in the endothelial differentiation gene 2 (EDG2). METHODS Five collections of samples, four from Europe and one from China, were studied. They included patients with 3 OA phenotypes: 1501 with knee OA, 1497 with hip OA and 376 with generalised OA. A total of 2521 controls were also studied. Allele and genotype frequencies of the rs10980705 SNP were analysed in each individual sample collection and in pooled data. In addition, a meta-analysis to incorporate results from the original Japanese report was performed. RESULTS The association of the rs10980705 SNP with knee OA was not replicated in any of the five sample collections studied or in their combined analysis (odds ratio (OR) 1.10, 95% CI 0.98 to 1.22; p = 0.10). Meta-analysis of all data, including the original Japanese study, did show association with knee OA (OR 1.15, 95% CI 1.06 to 1.26; p = 0.002) but the effect was accounted for by the Japanese data and was less significant than the original report. No association was found with hip OA or with generalised OA. CONCLUSIONS The original report of a promising genetic association between a druggable G-protein coupled receptor, EDG2, and knee OA has not been replicated. This lack of replication could be due to a modest effect of the promoter polymorphism that will require even larger studies (the winners curse) although a more pronounced effect in the Asian population vs Europeans cannot be excluded.
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Hofmann M, Stoss O, Shi D, Büttner R, van de Vijver M, Kim W, Ochiai A, Rüschoff J, Henkel T. Assessment of a HER2 scoring system for gastric cancer: results from a validation study. Histopathology 2008; 52:797-805. [DOI: 10.1111/j.1365-2559.2008.03028.x] [Citation(s) in RCA: 868] [Impact Index Per Article: 54.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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104
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Chen H, Ng WS, Shi D, Wee SB. Image registration based on virtual frame sequence analysis. Int J Comput Assist Radiol Surg 2007. [DOI: 10.1007/s11548-007-0121-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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105
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Zhou L, Yin W, Lu J, Shi D, Liu G, Di G, Wu J, Shen K, Lu H, Shen Z, Shao Z. A comparison of tumor characteristics between ER+/PR+ and ER+/PR- breast tumors in Chinese women. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.21097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
21097 Background: Although breast caner patients with any one of the two sex hormone receptors positive can be treated with endocrine therapy, many clinical data showed that there was different response to endocrine therapy for patients with ER+/PR+ and with ER+/PR- tumors. The aim of this study was to find out the factors related to PR expression by comparing the ER+/PR+ tumors and ER+/PR- tumors clinically and biologically. Methods: Between January 1990 to August 2006, 5,191 female breast cancer patients with known ER/PR expression status who received operation in our hospital were enrolled onto this retrospective study. Clinical and biological features of 2,227 patients with ER+/PR+ tumors were compared with those of 909 patients with ER+/PR- tumors. χ2 test was used for univariate analysis and logistic regression for multivariate analysis. Disease-free survival (DFS) and overall survival (OS) was calculated using Kaplan-Meier analyses, and all statistical tests were two-sided. Results: The peak onset age of patients with ER+/PR+ tumors and ER+/PR- tumors was 50, and it was significantly higher than that of patients with ER- tumors, which is 48(P=0.001). Univariate analysis showed that ER+/PR- tumors were larger in size, had more lymph nodes of metastasis, were higher in tumor grade than ER+/PR+ tumors. Furthermore, the expression of ER and CathepsinD was significantly lower, and CerbB-2 expression was higher in ER+/PR- tumors than in ER+/PR+ tumors. Multivariate analysis indicated that positive PR expression was associated with the level of ER(OR=1.792, P=0.000), CathepsinD(OR=1.380, P=0.035)and CerbB-2(OR=0.639, P=0.007). DFS(P=0.004) and OS(P=0.009) were higher among patients with PR-expressing tumors than with PR- negative tumors. Conclusions: ER+/PR+ tumors and ER+/PR- tumors may have the same etiology which is different from that of ER- tumors. Because of low ER level and changes of the expression of CerbB-2 and CathepsinD, the tumors that lacked PR expression display more aggressive features and have worse prognosis. According to these differences, new target of therapy and endocrine regimen may provide the possibility of improving the response and prognosis of endocrine therapy for patients with ER+/PR- tumors. No significant financial relationships to disclose.
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Wu R, Hu S, Xiao Y, Li Z, Shi D, Bi D. Development of Indirect Enzyme-linked Immunosorbent Assay with Nucleoprotein as Antigen for Detection and Quantification of Antibodies against Avian Influenza Virus. Vet Res Commun 2007; 31:631-41. [PMID: 17225082 DOI: 10.1007/s11259-007-3510-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2006] [Indexed: 11/24/2022]
Abstract
Avian influenza (AI) is a serious infectious disease caused by avian influenza virus (AIV) belonging to type A Orthomyxovirus. In the present study, we developed an indirect enzyme-linked immunosorbent assay (ELISA) employing E. coli-expressed full-length nucleoprotein (NP) of H9N2 avian influenza virus for the detection and quantification of antibodies against AIV nucleoprotein. The NP-ELISA was compared with the AI agar gel propagation (AGP) test, haemagglutination inhibition (HI) test, and IDEXX-FlockChek ELISA using 263 sera. The NP-ELISA was significantly more sensitive than the AGP and HI tests, and showed 96.2% agreement ratio with IDEXX-FlockChek ELISA. With results obtained using the NP-ELISA, an ELISA titre (ET) prediction equation, with which the ELISA titres of a flock or individual chickens can be determined, was derived from a positive/negative (P/N) ratio standard curve. The NP-ELISA enables an alternative rapid serological diagnosis and is suitable for influenza A antibody screening, especially in species that harbour several influenza subtypes.
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107
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Zhang RH, Shi D, Tjong SC, Li RKY. Study on the β to α transformation of polypropylene crystals in compatibilized blend of polypropylene/polyamide-6. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/polb.21287] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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108
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Xia W, Ping B, He X, Lee DF, Wei Y, Yu D, Mills G, Shi D, Hung MC. 591 POSTER Overexpression of IKKβ is correlated with cytoplasmic expression of p21CIP1/WAF1 in human breast cancers. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)70596-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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109
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Liu YE, Pu W, Jiang Y, Shi D, Dackour R, Shi YE. Chaperoning of estrogen receptor and induction of mammary gland proliferation by neuronal protein synuclein gamma. Oncogene 2006; 26:2115-25. [PMID: 17016445 DOI: 10.1038/sj.onc.1210000] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Synucleins are emerging as central players in the formation of pathologically insoluble deposits characteristic of neurodegenerative diseases. However, synuclein gamma (SNCG), previously identified as a breast cancer specific gene (BCSG1), is also highly associated with breast cancer progression. Using transgenic mouse model, we demonstrated a role of SNCG in induction of highly proliferative pregnancy-like phenotype of mammary epithelial cells and branching morphology. SNCG participated in the heat shock protein-based multiprotein chaperone complex for steroid receptor signaling. Expression of SNCG in mammary epithelium resulted in a significant stimulation of ERalpha transcriptional activity. SNCG-induced mammary gland proliferation can be effectively blocked by antiestrogen and ovariectomy, indicating that the induced proliferation is mediated by ERalpha signaling and requires estrogen stimulation. These data indicate the chaperone activity of SNCG on stimulation of steroid receptor signaling in mammary gland and, thus induces extensive mammary gland proliferation and contributes to the hormonal impact on mammary tumorigenesis.
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110
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Kaur M, Pop M, Shi D, Brignone C, Grossman SR. hHR23B is required for genotoxic-specific activation of p53 and apoptosis. Oncogene 2006; 26:1231-7. [PMID: 16924240 PMCID: PMC1804095 DOI: 10.1038/sj.onc.1209865] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Rad23 proteins function in both DNA repair and protein stability regulation. As ubiquitinated forms of p53 are stabilized after DNA damage in concert with p53 functional activation, and human Rad23 proteins (hHR23A and B) regulate p53 stability in unstressed cells, the role of hHR23B in post-genotoxin regulation of p53 was investigated. Depletion of hHR23B by specific short interfering RNA before genotoxic exposure attenuated p53, p21 and bax induction, abrogated the accumulation of ubiquitinated p53 and suppressed apoptosis. Expression of ubiquitin derivatives with all lysines mutated except K48 or K63 demonstrated that K48-linked p53-ubiquitin conjugates were specifically induced after DNA damage. hHR23B, along with native and ubiquitinated p53, accumulated in chromatin after genotoxic exposure, and the accumulation of ubiquitinated p53 in chromatin was prevented by hHR23B depletion. Chromatin immunoprecipitation analysis demonstrated that hHR23B and p53 both localized to the p21 promoter shortly after DNA damage. hHR23B thus plays a critical role in the activation and function of p53 after specific genotoxic exposures.
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111
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Shi D, Ye HQ, Yang QB, Kuo KH. A structural model of the icosahedral Al6Li3Cu phase studied by high-resolution electron microscopy. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/13642819108205567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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112
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Li XZ, Shi D, Kuo KH. Structure of Al3Mn, an orthorhombic approximant of the decagonal quasicrystal. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/13642819208207653] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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113
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Shi D, Chen F, Ng GS, Gao J. The construction of wavelet network for speech signal processing. Neural Comput Appl 2005. [DOI: 10.1007/s00521-005-0016-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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114
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Shi D, Yeung DS, Gao J. Sensitivity analysis applied to the construction of radial basis function networks. Neural Netw 2005; 18:951-7. [PMID: 15939573 DOI: 10.1016/j.neunet.2005.02.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2004] [Revised: 02/25/2005] [Accepted: 02/25/2005] [Indexed: 11/16/2022]
Abstract
Conventionally, a radial basis function (RBF) network is constructed by obtaining cluster centers of basis function by maximum likelihood learning. This paper proposes a novel learning algorithm for the construction of radial basis function using sensitivity analysis. In training, the number of hidden neurons and the centers of their radial basis functions are determined by the maximization of the output's sensitivity to the training data. In classification, the minimal number of such hidden neurons with the maximal sensitivity will be the most generalizable to unknown data. Our experimental results show that our proposed sensitivity-based RBF classifier outperforms the conventional RBFs and is as accurate as support vector machine (SVM). Hence, sensitivity analysis is expected to be a new alternative way to the construction of RBF networks.
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115
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Shi D, Yu X, Roth L, Morizono H, Allewell NM, Tuchman M. Structures of a novel N-acetyl-L-ornithine transcarbamylase. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305091920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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116
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Zhang J, Shi D, Anastasio M. SU-FF-J-79: Local Tomography Using Adapted Feldkamp and Expectation Maximization Algorithms. Med Phys 2005. [DOI: 10.1118/1.1997625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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117
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Grey W, Olavson T, Shi D. The role of e-marketplaces in relationship-based supply chains: A survey. ACTA ACUST UNITED AC 2005. [DOI: 10.1147/sj.441.0109] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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118
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Kasai Y, Shi D, Sugimoto T, Takegami K, Uchida A. Outcome of late surgical treatment in patients with incomplete paraplegia due to spinal degenerative diseases. Spinal Cord 2004; 43:171-4. [PMID: 15534624 DOI: 10.1038/sj.sc.3101676] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
STUDY DESIGN Retrospective analysis. OBJECTIVE To assess the outcome of late surgical intervention in patients with incomplete paraplegia due to spinal degenerative diseases. SETTING Three men and four women with cervical or thoracic spinal degenerative diseases, who preoperatively were unable to walk for more than 6 months in Mie prefecture, Japan. METHODS Review of clinical records and questionnaire survey regarding the walking ability of patients 2 years after surgery. RESULTS All seven patients were unable to walk postoperatively. CONCLUSION A late surgical intervention may not lead to functional recovery in patients with spinal degenerative disease who were unable to walk for at least 6 months.
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Stoica A, Wang XL, Horton D, Tian H, Yang L, Richardson J, Maxey E, Liaw P, Shi D. Neutron Diffraction Study of Fatigue Behaviors in 316LN Stainless Steel. JOURNAL OF NEUTRON RESEARCH 2004. [DOI: 10.1080/10238160410001734522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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120
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Sudo A, Sano T, Horikawa K, Yamakawa T, Shi D, Uchida A. The incidence of deep vein thrombosis after hip and knee arthroplasties in Japanese patients: a prospective study. J Orthop Surg (Hong Kong) 2003; 11:174-7. [PMID: 14676343 DOI: 10.1177/230949900301100212] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
PURPOSE To document the incidence of proximal deep vein thrombosis and pulmonary embolism in 58 consecutive Japanese patients undergoing total hip arthroplasty or total knee arthroplasty. METHODS Patients were routinely examined for proximal deep vein thrombosis by B-mode ultrasonography before and after surgery. Those patients who had ultrasonographic findings of deep vein thrombosis were also investigated for pulmonary embolism by ventilation-perfusion lung scan. RESULTS The incidence of deep vein thrombosis after total hip arthroplasty and total knee arthroplasty were 9.1% and 4.0% respectively, and the incidence of pulmonary embolism were 3.0% and 0%, respectively. There were no cases of fatal pulmonary embolism. CONCLUSION The incidence of deep vein thrombosis and pulmonary embolism in Japanese patients may have increased over the last few decades.
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121
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Grey W, Katircioglu K, Bagchi S, Shi D, Gallego G, Seybold D, Stefanis S. An analytic approach for quantifying the value of e-business initiatives. ACTA ACUST UNITED AC 2003. [DOI: 10.1147/sj.423.0484] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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122
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Giraudoux P, Craig PS, Delattre P, Bao G, Bartholomot B, Harraga S, Quéré JP, Raoul F, Wang Y, Shi D, Vuitton DA. Interactions between landscape changes and host communities can regulate Echinococcus multilocularis transmission. Parasitology 2003; 127 Suppl:S121-31. [PMID: 15027609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
An area close to the Qinghai-Tibet plateau region and subject to intensive deforestation contains a large focus of human alveolar echinococcosis while sporadic human cases occur in the Doubs region of eastern France. The current review analyses and compares epidemiological and ecological results obtained in both regions. Analysis of rodent species assemblages within quantified rural landscapes in central China and eastern France shows a significant association between host species for the pathogenic helminth Echinococcus multilocularis, with prevalences of human alveolar echinococcosis and with land area under shrubland or grassland. This suggests that at the regional scale landscape can affect human disease distribution through interaction with small mammal communities and their population dynamics. Lidicker's ROMPA hypothesis helps to explain this association and provides a novel explanation of how landscape changes may result in increased risk of a rodent-borne zoonotic disease.
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Shi D, Daniels RL. A survey of manufacturing flexibility: Implications for e-business flexibility. ACTA ACUST UNITED AC 2003. [DOI: 10.1147/sj.423.0414] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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124
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Fu X, Jiang G, Wu K, Zhu X, Shi D, Xu L, Zhao S. [Multivariate analysis for prognostic predictors in non-small cell lung cancer]. ZHONGGUO FEI AI ZA ZHI = CHINESE JOURNAL OF LUNG CANCER 2001; 4:459-62. [PMID: 21106159 DOI: 10.3779/j.issn.1009-3419.2001.06.18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND To determine the prognostic predictors for non-small cell lung cancer ( NSCLC) with multivariate analysis. METHODS From 1981 to 1994, 158 patients with NSCLC had been treated by surgery alone or combined with radiotherapy and/ or chemotherapy . Their clinical characteristics were collected. All histological slides were reviewed to evaluate the histological type, tumor differentiation and vascular and lymphatic vessel invasion. Oncoprotein overexpressions were measured by immunohistochemistry assay ( ABC) , including Pan-ras, c-myc, c-erb B2, EGFR and p53. PCNA was also measured by ABC. The endpoints for prognosis consisted of survival, local control and distant metastasis. They were calculated by Kaplan-Meier method with Log-rank test determining the difference between subgroups. Cox model was used for multivariate analysis. The prognostic index ( PI) was calculated basing on the results of multivariate analysis, then the high risk group was determined by PI. RESULTS The overall actual 5-year survival rate was 44%. The unfavorable predictors were late T and N of TNM stage ( P = 0. 025 and < 0. 001) , lymphatic vessel invasion ( P= 0. 002) and multi-oncoprotein overexpression ( P= 0. 018) . The overall median of PI was 1. 71( 0. 23-3. 75) . The patients were divided into three groups: good prognosis group ( 42 cases, PI ≤ 1. 3) , moderate prognosis group ( 63 cases, 1. 3 < PI ≤ 2. 2) and bad prognosis group ( 53 cases, PI > 2. 2) . There was significant difference in survival rate among the three groups ( P < 0. 001) , 5-year survival rate was 77%, 45% and 21%, respectively. CONCLUSIONS The unfavorable predictors are late T, late N, lymphatic vessel invasion and multi-oncoprotein overexpression. PI could be used to determine the high risk group in patients with NSCLC.
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Mavinakere M, Morizono H, Shi D, Allewell NM, Tuchman M. The clinically variable R40H mutant ornithine carbamoyltransferase shows cytosolic degradation of the precursor protein in CHO cells. J Inherit Metab Dis 2001; 24:614-22. [PMID: 11768581 DOI: 10.1023/a:1012726207870] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Ornithine carbamoyltransferase (OCT) deficiency is now frequently found in adults with hyperammonaemia affected by mutations that cause partial deficiency of this urea cycle enzyme. One of these mutations (R40H) has occurred in several families and has been found also in asymptomatic relatives. To better understand the phenotypic heterogeneity of this recurrent mutation, we investigated the biological properties of the mutant protein. Using 35S labelling, the import and processing of the R40H mutant OCT protein was investigated in intact CHO cells and in isolated rat liver mitochondria and compared to the wild type and R141Q mutant that causes complete enzyme deficiency. The R40H OCT protein seems to be imported and processed by the mitochondria in a manner similar to that of wild type. However, it is consistently degraded to a smaller fragment in the intact cells, unlike the wild type and R141Q mutant. The mature form of the enzyme is not susceptible to degradation. These data, obtained in CHO cells, suggest that deficiency in OCT enzymatic function conferred by the R40H mutation is likely caused by enhanced degradation of the preprotein in the cytosol. We propose therefore that variation in the rate of OCT turnover is responsible for the heterogeneity of the clinical phenotype in these patients.
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